I have a timber-frame wall with hemp lime insulation finished inside and out with a hemplime render.

It was originally painted with Biofa mineral paint. This has proved to be ineffective. It is powdery and is washing away over time. It is possible that it was painted poorly and with incorrect preparation. I am about to re-paint it and am considering using Beeck - Renosil- a waterglass based mineral paint similar to Keim mineral paint.

However this paint is very expensive, and given the previous failure of the mineral paint - I am also considering a more modern paint such as Sandtex or Weathershield but with these I have concerns about the lower breathablilty of acrylic paint.

So my questions are:

Has anyone got first hand information about the sucess or otherwise of Beeck Renosil mineral paint lasting and weathering very well? (8, 10 years or more)

Or, has anyone used a Sandtex type modern acrylic paint on a hemplime wall and if so how is it it working out?

I would use Sandtex or Weathersheild if I knew that there was no negative build up of moisture in the wall, or the paint flaking off etc.

Our house is painted with Beeckosil (lime walls). It's been on for a couple of years now and seems fine. I think the important thing is to follow the manufacturer's instructions carefully regarding preparation.

I would never use acrylic paints. Spent thousands having them sensitively removed from the house. They are wonderful when first applied, but you get the odd crack that lets in water, and being waterproof the paint doesn't let the water out again.

My walls were soaking wet. Removing the paint from brick fixed some damp problems on the upper floors, but unfortunately I had to replace a timber gable wall that had been wet enough for long enough to for the structure to disappear.

I limewashed the render. Tub of lime putty is about Â£10 and will do the whole house and is very well suited to a hemp wall. Needs a bunch of coats, and it won't last for ever, but that is what would have kept the building going for the previous 300 years so can't be all bad. Mine is still immaculate after 3 years. House has been going for about 400 years.

I wound up using Beek BS+. We have part pointed granite and part bag rubbed granite (so white). The BS+ didn't need etching, which sounded like a potential pita and covered the whole building. I did it 3-4 years ago & it seems fine, I remember noticing mist balling up on it, a bit like the DWR treatment on a waterproof jacket. It was cheaper at the time in Germany, but I got it pretty much price matched in the uk which gave me the possibility of returning any excess. Finding the correct conditions to apply it required planning - dry, but not too windy and not in direct sunlight. Fortunately we had a spell of decent weather & I did the back & end of the house (S & W) in the mornings & the front (E) in the afternoon. I think it was money well spent & will redo it in a few years when needed the same way.